Conventional film deposition apparatuses (such as CVD apparatuses and PVD apparatuses) and plasma etching apparatuses used for manufacturing semiconductor devices such as ICs and LSIs include a stage for accurately holding a wafer in a vacuum process chamber. As such a stage, for example, a substrate fixing device that attracts and holds a wafer using an electrostatic chuck mounted on a baseplate has been proposed.
Some electrostatic chucks are provided with a heating element for controlling wafer temperature. In this case, a temperature sensor for detecting the surface temperature of the electrostatic chuck is provided in the electrostatic chuck, and the heating element is controlled based on the surface temperature of the electrostatic chuck monitored with the temperature sensor to control wafer temperature (see, for example, Japanese Laid-open Patent Publication No. 2016-72478).